Eric, At www.echolink.com, the echolink folks, sell an interface board for it. It is a small ~3x3 board with serial port to the computer and I/O for the repeater. They provide tx an rx audio and ptt. Think also COS. Been about 5 years since I played with ours. It is still running 24/7.
The control board has a DTMF decoder and allows one thru the repeater access nodes, turn on/off connections, enable/disable the echolink, etc. I think it cost about $50. We use one here and it simplified things greatly. The only problem was the audio...the computers often are not at ground and hum can be a problem. 73, ron, n9ee/r >From: kk2ed <[EMAIL PROTECTED]> >Date: 2007/08/19 Sun PM 12:15:23 CDT >To: [email protected] >Subject: [Repeater-Builder] Simple COR & PTT to Echolink serial port interface > >Good Afternoon, > >Has anyone come up with a simple circuit to tie a repeater >controller's port to a PC's serial port for Echolink? > >I have customized a few Rigblaster type units in the past to add COS >funtionality, but the more I have looked at them, the more I think >they are a waste of money. > >A simple circuit consisting of a few parts should be enough to adapt >RTS or DTR for a COS signal to the controller, and the controller's >PTT to the PC's DSR or DCD input. Most of the commercial interface >boxes don't really offer any advantage to the audio paths, so hooking >the sound card directly to the controller's audio in/out paths >shouldn't be a problem. > >In the past I've simply tied a radio's COS to the PC's DCD input via >an isolation diode and current-limiting resistor with great success, >and used the DTR to trigger an NPN transistor across the radio's PTT, >but obviously things are reversed on a controller. I was figuring I >could use RTS as the controller's COS signal, and set the active >hi/lo on the controller accordingly. For the PTT signal, I might need >to invert the PTT output of the controller to control DSC or DCD in >the right active direction. > >Anyone have any suggestions or documented circuits before I embark on >this project? > >Eric >KE2D > > Ron Wright, N9EE 727-376-6575 MICRO COMPUTER CONCEPTS Owner 146.64 repeater Tampa Bay, FL No tone, all are welcome.
